Need help with savestate! Mupen64.

alright, so I need to load a Mupen64 Savestate. but When I download Mupen64 (i've literally tried like 5 different websites) they're ALL missing the RSP plugin. Which means I can't even load a rom. I've got no idea how to get one either. I googled for a bit and there were tons of the people with the same problem, and people were just saying "get mupen64plus, its newer". Well I can't do that, because the Save-state is for Mupen64. Not mupen64+. Can someone show me how to get an RSP plugin for mupen64, or if there is a way to convert the savestate that would also be helpful.